/*
Kakine
ActionScript Framework
Copyright © 2011, PUNY, LLC.

This file is part of KAKINE.

KAKINE is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

KAKINE is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with KAKINE.  If not, see <http://www.gnu.org/licenses/>.
*/ 
package com.puny.utils.easing
{
	public class TrigonometricEasing extends Easing implements IEasing
	{
		private var _start:Number;
		private var _end:Number;
		private var _length:Number;
		public function TrigonometricEasing(start:Number, end:Number, count:uint)
		{
			_start = start;
			_end = end;
			frame = count;
			_length = _end - _start;
		}

		public function forward():Number
		{
			var pp:Number;
			if (isMoving()) {
				pos++;
				pp = _start + _length / 2 * (1-Math.cos(Math.PI*pos/frame));
			} else {
				pp = _end;
			}
			return pp;
		}
		
	}
}